Frame broke in half (pics)

[79Beast]

This was over a year ago, but I feel like posting pics so here you are. The end result was the truck folded up like a dump truck and two of my friends pulling winch cable so that I can winch to the top of a very steep hill. The frame broke on both sides inbetween the cab and bed. About one inch of the bottom part of the frame on each side held it together. I limped it off the trail with one front wheel pulling. The rear driveshaft slip yoke slammed together and popped a cap of the Ujoint and I grenaded a front hub.

 

[79k20350]

Thats pretty scary

 

[big83chevy4x4]

the location makes me wonder if the frame flex that is mostly noticable between the cab and the box is in such a small area of frame that it finely fatigued and cracked.

also the pic looks like the crack has been there a while, then the bottom 1/3 finely let loose.

what was the fix for this? new frame or weld it back together?

 

[roadnotca]

The whole truck looks like a "test to destruction" sample.

 

[beater_k20]

i've actually seen that quite a bit, ours usually bend the other way. guess that's what you get when you slam two trucks together. most commonly around here the old 3/4 tons that have been worked VERY hard generally have it. causes the truck to bend in a U shape.

 

[gmc4cw]

considering the rest of the truck, did you just swap the drive train into something less beat?

 

[walla2k5]

Had a '73 3/4 ton do something similar,just one side,not to that extent though.

 

[NoReGrEtS]

dude your truck just wanted to be back halfed and linked so she gave you a hand

 

[diesel4me]

Time to build a "Weldernator"....

I've only seen a few GM frames fail,usually up here rust is what causes them to fail,not stress cracks..only one or two I've seen had cracks like that,and they were on 1 ton ramp trucks, that were often overloaded badly(or had frame damage caused by an inexperienced operator--its very possible to bend a frame easily with the hydraulic pistons that tilt the bed, if you dont know what your doing! )...

..that is the first place most trucks that are carrying heavy loads,or flex a lot, will bend or fail,and I see a lot of frames that have been "doubled up", or had added reinforcement in that area...my 74 K20 was about ready to fold in two there,you could feel the frame flexing badly and the bed would hit the cab on bumps and while crawling over uneven terrain..it was real thin there,only 1/8" thick at most..thats when I decided to scrap it...

It's times like this a "weldernator" or onboard welder would be priceless..it appears you could probably weld the cracks back up and add some 1/4" plates to beef it up there,after bending it back where it belongs..

 

[scooter122983]

Mine almost did that completly the only piece that was holding it togather was the top of the frame. I put a jack on the bottom and straightened it and welded it with some 6011 i plan on getting some plate and fixing it for good. By the way does any one here have a piece of 12x6x.125 piece of plate that I can take off there hands.

 

[79Beast]

This reply is late, but...I limped it back to the trailer in front left wheel drive. At home, I pulled the bed and used grinder and a couple hi-lift jacks to get the halves lined back up about right. I had a buddy helping my and we used some different sized pieces of 1/4" place (scrap I had laying around) to reinforce the broken area after butt-welding it back. Although the truck hasn't run in the last 10 months, it held up through several pretty severe runs.
As for the truck looking like it got hit by a "wrinkle bomb", it's nice to not be worried about the sheet metal. Contact with rocks and trees is no big deal. As long as the doors still open and close enough to keep out the rain, I'm good with it.